Access keys:

Status of Levees and Channels > FEMA Floodplain Maps

FEMA Floodplain Maps

New FEMA floodplain maps are available now.

You can download detailed maps by clicking on the highligted squares in the grid below. NOTE: files are very large - 8-11 MB

Flood Zone Classification Legend is below the image.

FEMA Grid C0259G C0266G C0267G C0267G

Flood Zone Classification Legend

SPECIAL FLOOD HAZARD AREAS SUBJECT TO INUNDATION BY THE 1% ANNUAL CHANCE FLOOD

The 1% annual flood (100-year flood), also known as the base flood, is the flood that has a 1% chance of being equaled or exceeded in any given year. The Special F lood Hazard Area is the area subject to flooding by the 1% annual chance flood. Areas of Special Flood Hazard include Zones A, AE, AH, AO, AR, A99, V, and VE. The Base Flood Elevation is the water-surface elevation of the 1% annual chance flood.

  • ZONE A No Base Flood Elevations determined.
  • ZONE AE Base Flood Elevations determined.
  • ZONE AH Flood depths of 1 to 3 feet (usually areas of ponding); Base Flood Elevations determined.
  • ZONE AO Flood depths of 1 to 3 feet (usually sheet flow on sloping terrain); averagedepths determined. For areas of alluvial fan flooding, velocities alsodetermined.
  • ZONE AR Special Flood Hazard Area formerly protected from the 1% annual chanceflood by a flood control system that wassubsequently decertified. Zone A Rindicates that the former flood control system is being restored to provide protection from the 1% annual chance or greater flood.
  • ZONE A99 Area to be protected from 1% annual chance flood by a Federal floodprotection system under construction; no Base Flood Elevations determined.
  • ZONE V Coastal flood zone with velocity hazard (wave action); no Base Flood Elevations determined.
  • ZONE VE Coastal flood zone with velocity hazard (wave action); Base FloodElevations determined.

FLOODWAY AREAS IN ZONE AE

The floodway is the channel of a stream plus any adjacent floodplain areas that must be kept free of encroachment so that the 1% annual chance flood can be carried without substantial increases in flood heights.

OTHER FLOOD AREAS

  • ZONE X Areas of 0.2% annual chance flood; areas of 1% annual chance flood with average depths of less than 1 foot or with drainage areas less than 1 square mile; and areas protected by levees from 1% annual chance flood.

OTHER AREAS

  • ZONE X Areas determined to be outside the 0.2% annual chance floodplain.
  • ZONE D Areas in which flood hazards are undetermined, but possible.
  • ZONE OW Open water.
  • ZONE P2FH 0.2% annual change flood - moderate flood zone area also known as the 500-year flood zone.